From patchwork Mon Oct 24 09:13:54 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Thi=C3=A9baud_Weksteen?= X-Patchwork-Id: 13016906 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EB79AC38A2D for ; Mon, 24 Oct 2022 09:14:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229816AbiJXJOv (ORCPT ); Mon, 24 Oct 2022 05:14:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50428 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230322AbiJXJOq (ORCPT ); Mon, 24 Oct 2022 05:14:46 -0400 Received: from mail-pf1-x44a.google.com (mail-pf1-x44a.google.com [IPv6:2607:f8b0:4864:20::44a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D7F4210FCD for ; Mon, 24 Oct 2022 02:14:27 -0700 (PDT) Received: by mail-pf1-x44a.google.com with SMTP id i19-20020aa787d3000000b0056bd68d713cso750524pfo.17 for ; Mon, 24 Oct 2022 02:14:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=content-transfer-encoding:cc:to:from:subject:message-id :mime-version:date:from:to:cc:subject:date:message-id:reply-to; bh=VnMmmenO3Z6xhx6n/n6yKT565qZLwfdm6Yu2HAVrDZ8=; b=IcX/WrI/UvCe09o4Shj8UkVVXYEqrQEaGoYkQjokptM7wYr1nXgZfaLHvYz0/6g4OX i1IpYjh5daWCC9khF6UqWwpdr0m3oDTcD8aFL3W5Fk0zQZRFRQ3lVFnouzWuE/oWq08l ykr7C2CzO5KCgt/tGmb1saxOPpDWgQ7XjRsy5JynbiYxUePhryl7sIz9tts9TDrq+4nk 1cACXMAY4fjufPAR1R4Lb6/FqH9vdTt2zuOXMmMPcMMookyxbwDvMb6sKWEFSz+J8GJZ gXYD7NLAPho4iGAkgOY9I7uwhvDUymjXEsi6mukuxPh/+BaIZLT8XtutQRm2C38FClyH tIvA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:cc:to:from:subject:message-id :mime-version:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=VnMmmenO3Z6xhx6n/n6yKT565qZLwfdm6Yu2HAVrDZ8=; b=61FtbDzgcl6Ttowy/zREbMi5CGg0xv9GLmZP4PCx3OjbGFhDuy3i7SESGZaSTsJgHp 6Fiv+STebtZDlvBHL4KDyckDox5elnaYrsO72fv6DnwrZnrZy1gu9lnPKTdVw+/S7FB5 RShBsKwIrM9LDjo9jW8v1gJv30OoJx9K9tBNNwsXrGWhEalG3A7GFkD2DS5kPr/QnaVv gEzFHdJ/BUfQ84oB0sdcICz9K/H7MZP+VFlIqveaN81m0kjCKKVChFM1XgZ9k2nKeU+d HiKUowlEHfez/u/NHdUTAP4KKeI4qJanggq5z4Ed6QEHk3y9P7s883qQgONnXoDv5jVx 7hfw== X-Gm-Message-State: ACrzQf1YipOzk+TDnVey8l0rNzSyAYQgRFV8IT6aHAcQLOD+XCDihmxn M+l20/sv8ZWTXlQzTcI1g3347NEXzO9vE10VEk9nfofx9dix0xi4k8p7ckG96tRhy8TuWD+Iyzj FjjqKV76ELXZXqAbG1vjQRDqLV8YunkIXCpTCIWt1Mholy+wMLFawDyJpsw/Q X-Google-Smtp-Source: AMsMyM4xT/AHchtdwVAn233384mOTaVDO0gc3Eqar055je1iPqhP9OGNp4RBPULFOZ1ZX1h9qbtPXhc2mg== X-Received: from tweek-sin.c.googlers.com ([fda3:e722:ac3:cc00:4f:4b78:c0a8:2bfd]) (user=tweek job=sendgmr) by 2002:a17:902:b942:b0:178:be25:203f with SMTP id h2-20020a170902b94200b00178be25203fmr33054139pls.101.1666602853650; Mon, 24 Oct 2022 02:14:13 -0700 (PDT) Date: Mon, 24 Oct 2022 20:13:54 +1100 Mime-Version: 1.0 X-Mailer: git-send-email 2.38.0.135.g90850a2211-goog Message-ID: <20221024091354.2253669-1-tweek@google.com> Subject: [PATCH] libselinux: ignore invalid class name lookup From: " =?utf-8?q?Thi=C3=A9baud_Weksteen?= " To: selinux@vger.kernel.org Cc: James Carter , Paul Moore , Jeffrey Vander Stoep , " =?utf-8?q?Thi=C3=A9baud_Weksteen?= " Precedence: bulk List-ID: X-Mailing-List: selinux@vger.kernel.org selinux_check_access relies on string_to_security_class to resolve the class index from its char* argument. There is no input validation done on the string provided. It is possible to supply an argument containing trailing backslashes (i.e., "sock_file//////") so that the paths built in discover_class get truncated. The processing will then reference the same permission file multiple time (e.g., perms/watch_reads will be truncated to perms/watch). This will leak the memory allocated when strdup'ing the permission name. The discover_class_cache will end up in an invalid state (but not corrupted). Ensure that the class provided does not contain any path separator. Signed-off-by: Thiébaud Weksteen Acked-by: James Carter --- libselinux/src/stringrep.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/libselinux/src/stringrep.c b/libselinux/src/stringrep.c index 2fe69f43..592410e5 100644 --- a/libselinux/src/stringrep.c +++ b/libselinux/src/stringrep.c @@ -63,6 +63,9 @@ static struct discover_class_node * discover_class(const char *s) return NULL; } + if (strchr(s, '/') != NULL) + return NULL; + /* allocate a node */ node = malloc(sizeof(struct discover_class_node)); if (node == NULL)